/**
 * @file
 * lwIP network interface abstraction
 *
 */

/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 */

#include "lwip/opt.h"

#include "lwip/def.h"
#include "lwip/ip_addr.h"
#include "lwip/netif.h"
#include "lwip/tcp.h"
#include "lwip/snmp.h"
#include "lwip/igmp.h"
#include "netif/etharp.h"
#if ENABLE_LOOPBACK
	#include "lwip/sys.h"
	#if LWIP_NETIF_LOOPBACK_MULTITHREADING
		#include "lwip/tcpip.h"
	#endif /* LWIP_NETIF_LOOPBACK_MULTITHREADING */
#endif /* ENABLE_LOOPBACK */

#if LWIP_AUTOIP
	#include "lwip/autoip.h"
#endif /* LWIP_AUTOIP */
#if LWIP_DHCP
	#include "lwip/dhcp.h"
#endif /* LWIP_DHCP */

#if LWIP_NETIF_STATUS_CALLBACK
	#define NETIF_STATUS_CALLBACK(n) { if (n->status_callback) (n->status_callback)(n); }
#else
	#define NETIF_STATUS_CALLBACK(n) { /* NOP */ }
#endif /* LWIP_NETIF_STATUS_CALLBACK */

#if LWIP_NETIF_LINK_CALLBACK
	#define NETIF_LINK_CALLBACK(n) { if (n->link_callback) (n->link_callback)(n); }
#else
	#define NETIF_LINK_CALLBACK(n) { /* NOP */ }
#endif /* LWIP_NETIF_LINK_CALLBACK */

struct netif* netif_list;
struct netif* netif_default;

/**
 * Add a network interface to the list of lwIP netifs.
 *
 * @param netif a pre-allocated netif structure
 * @param ipaddr IP address for the new netif
 * @param netmask network mask for the new netif
 * @param gw default gateway IP address for the new netif
 * @param state opaque data passed to the new netif
 * @param init callback function that initializes the interface
 * @param input callback function that is called to pass
 * ingress packets up in the protocol layer stack.
 *
 * @return netif, or NULL if failed.
 */
struct netif*
netif_add(struct netif* netif, struct ip_addr* ipaddr, struct ip_addr* netmask,
          struct ip_addr* gw,
          void* state,
          err_t (* init)(struct netif* netif),
          err_t (* input)(struct pbuf* p, struct netif* netif))
{
	static u8_t netifnum = 0;

	/* reset new interface configuration state */
	netif->ip_addr.addr = 0;
	netif->netmask.addr = 0;
	netif->gw.addr = 0;
	/* netif->flags = 0; */

#if LWIP_DHCP
	/* netif not under DHCP control by default */
	netif->dhcp = NULL;
#endif /* LWIP_DHCP */
#if LWIP_AUTOIP
	/* netif not under AutoIP control by default */
	netif->autoip = NULL;
#endif /* LWIP_AUTOIP */
#if LWIP_NETIF_STATUS_CALLBACK
	netif->status_callback = NULL;
#endif /* LWIP_NETIF_STATUS_CALLBACK */
#if LWIP_NETIF_LINK_CALLBACK
	netif->link_callback = NULL;
#endif /* LWIP_NETIF_LINK_CALLBACK */
#if LWIP_IGMP
	netif->igmp_mac_filter = NULL;
#endif /* LWIP_IGMP */
#if ENABLE_LOOPBACK
	netif->loop_first = NULL;
	netif->loop_last = NULL;
#endif /* ENABLE_LOOPBACK */

	/* remember netif specific state information data */
	netif->state = state;
	netif->num = netifnum++;
	netif->input = input;
#if LWIP_NETIF_HWADDRHINT
	netif->addr_hint = NULL;
#endif /* LWIP_NETIF_HWADDRHINT*/
#if ENABLE_LOOPBACK && LWIP_LOOPBACK_MAX_PBUFS
	netif->loop_cnt_current = 0;
#endif /* ENABLE_LOOPBACK && LWIP_LOOPBACK_MAX_PBUFS */

	netif_set_addr(netif, ipaddr, netmask, gw);

	/* call user specified initialization function for netif */
	if(init(netif) != ERR_OK) {
		return NULL;
	}

	/* add this netif to the list */
	netif->next = netif_list;
	netif_list = netif;
	snmp_inc_iflist();

#if LWIP_IGMP

	/* start IGMP processing */
	if(netif->flags & NETIF_FLAG_IGMP) {
		igmp_start(netif);
	}

#endif /* LWIP_IGMP */

	LWIP_DEBUGF(NETIF_DEBUG, ("netif: added interface %c%c IP addr ",
	                          netif->name[0], netif->name[1]));
	ip_addr_debug_print(NETIF_DEBUG, ipaddr);
	LWIP_DEBUGF(NETIF_DEBUG, (" netmask "));
	ip_addr_debug_print(NETIF_DEBUG, netmask);
	LWIP_DEBUGF(NETIF_DEBUG, (" gw "));
	ip_addr_debug_print(NETIF_DEBUG, gw);
	LWIP_DEBUGF(NETIF_DEBUG, ("\n"));
	return netif;
}

/**
 * Change IP address configuration for a network interface (including netmask
 * and default gateway).
 *
 * @param netif the network interface to change
 * @param ipaddr the new IP address
 * @param netmask the new netmask
 * @param gw the new default gateway
 */
void
netif_set_addr(struct netif* netif, struct ip_addr* ipaddr, struct ip_addr* netmask,
               struct ip_addr* gw)
{
	netif_set_ipaddr(netif, ipaddr);
	netif_set_netmask(netif, netmask);
	netif_set_gw(netif, gw);
}

/**
 * Remove a network interface from the list of lwIP netifs.
 *
 * @param netif the network interface to remove
 */
void netif_remove(struct netif* netif)
{
	if(netif == NULL) return;

#if LWIP_IGMP

	/* stop IGMP processing */
	if(netif->flags & NETIF_FLAG_IGMP) {
		igmp_stop(netif);
	}

#endif /* LWIP_IGMP */

	snmp_delete_ipaddridx_tree(netif);

	/*  is it the first netif? */
	if(netif_list == netif) {
		netif_list = netif->next;
		snmp_dec_iflist();
	} else {
		/*  look for netif further down the list */
		struct netif* tmpNetif;

		for(tmpNetif = netif_list; tmpNetif != NULL; tmpNetif = tmpNetif->next) {
			if(tmpNetif->next == netif) {
				tmpNetif->next = netif->next;
				snmp_dec_iflist();
				break;
			}
		}

		if(tmpNetif == NULL)
			return; /*  we didn't find any netif today */
	}

	/* this netif is default? */
	if(netif_default == netif)
		/* reset default netif */
		netif_set_default(NULL);

	LWIP_DEBUGF(NETIF_DEBUG, ("netif_remove: removed netif\n"));
}

/**
 * Find a network interface by searching for its name
 *
 * @param name the name of the netif (like netif->name) plus concatenated number
 * in ascii representation (e.g. 'en0')
 */
struct netif*
netif_find(char* name)
{
	struct netif* netif;
	u8_t num;

	if(name == NULL) {
		return NULL;
	}

	num = name[2] - '0';

	for(netif = netif_list; netif != NULL; netif = netif->next) {
		if(num == netif->num &&
		        name[0] == netif->name[0] &&
		        name[1] == netif->name[1]) {
			LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: found %c%c\n", name[0], name[1]));
			return netif;
		}
	}

	LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: didn't find %c%c\n", name[0], name[1]));
	return NULL;
}

/**
 * Change the IP address of a network interface
 *
 * @param netif the network interface to change
 * @param ipaddr the new IP address
 *
 * @note call netif_set_addr() if you also want to change netmask and
 * default gateway
 */
void
netif_set_ipaddr(struct netif* netif, struct ip_addr* ipaddr)
{
	/* TODO: Handling of obsolete pcbs */
	/* See:  http://mail.gnu.org/archive/html/lwip-users/2003-03/msg00118.html */
#if LWIP_TCP
	struct tcp_pcb* pcb;
	struct tcp_pcb_listen* lpcb;

	/* address is actually being changed? */
	if((ip_addr_cmp(ipaddr, &(netif->ip_addr))) == 0) {
		/* extern struct tcp_pcb *tcp_active_pcbs; defined by tcp.h */
		LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_STATE, ("netif_set_ipaddr: netif address being changed\n"));
		pcb = tcp_active_pcbs;

		while(pcb != NULL) {
			/* PCB bound to current local interface address? */
			if(ip_addr_cmp(&(pcb->local_ip), &(netif->ip_addr))) {
				/* this connection must be aborted */
				struct tcp_pcb* next = pcb->next;
				LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_STATE, ("netif_set_ipaddr: aborting TCP pcb %p\n", (void*)pcb));
				tcp_abort(pcb);
				pcb = next;
			} else {
				pcb = pcb->next;
			}
		}

		for(lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
			/* PCB bound to current local interface address? */
			if((!(ip_addr_isany(&(lpcb->local_ip)))) &&
			        (ip_addr_cmp(&(lpcb->local_ip), &(netif->ip_addr)))) {
				/* The PCB is listening to the old ipaddr and
				 * is set to listen to the new one instead */
				ip_addr_set(&(lpcb->local_ip), ipaddr);
			}
		}
	}

#endif
	snmp_delete_ipaddridx_tree(netif);
	snmp_delete_iprteidx_tree(0, netif);
	/* set new IP address to netif */
	ip_addr_set(&(netif->ip_addr), ipaddr);
	snmp_insert_ipaddridx_tree(netif);
	snmp_insert_iprteidx_tree(0, netif);

	LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("netif: IP address of interface %c%c set to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
	            netif->name[0], netif->name[1],
	            ip4_addr1(&netif->ip_addr),
	            ip4_addr2(&netif->ip_addr),
	            ip4_addr3(&netif->ip_addr),
	            ip4_addr4(&netif->ip_addr)));
}

/**
 * Change the default gateway for a network interface
 *
 * @param netif the network interface to change
 * @param gw the new default gateway
 *
 * @note call netif_set_addr() if you also want to change ip address and netmask
 */
void
netif_set_gw(struct netif* netif, struct ip_addr* gw)
{
	ip_addr_set(&(netif->gw), gw);
	LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("netif: GW address of interface %c%c set to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
	            netif->name[0], netif->name[1],
	            ip4_addr1(&netif->gw),
	            ip4_addr2(&netif->gw),
	            ip4_addr3(&netif->gw),
	            ip4_addr4(&netif->gw)));
}

/**
 * Change the netmask of a network interface
 *
 * @param netif the network interface to change
 * @param netmask the new netmask
 *
 * @note call netif_set_addr() if you also want to change ip address and
 * default gateway
 */
void
netif_set_netmask(struct netif* netif, struct ip_addr* netmask)
{
	snmp_delete_iprteidx_tree(0, netif);
	/* set new netmask to netif */
	ip_addr_set(&(netif->netmask), netmask);
	snmp_insert_iprteidx_tree(0, netif);
	LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("netif: netmask of interface %c%c set to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
	            netif->name[0], netif->name[1],
	            ip4_addr1(&netif->netmask),
	            ip4_addr2(&netif->netmask),
	            ip4_addr3(&netif->netmask),
	            ip4_addr4(&netif->netmask)));
}

/**
 * Set a network interface as the default network interface
 * (used to output all packets for which no specific route is found)
 *
 * @param netif the default network interface
 */
void
netif_set_default(struct netif* netif)
{
	if(netif == NULL) {
		/* remove default route */
		snmp_delete_iprteidx_tree(1, netif);
	} else {
		/* install default route */
		snmp_insert_iprteidx_tree(1, netif);
	}

	netif_default = netif;
	LWIP_DEBUGF(NETIF_DEBUG, ("netif: setting default interface %c%c\n",
	                          netif ? netif->name[0] : '\'', netif ? netif->name[1] : '\''));
}

/**
 * Bring an interface up, available for processing
 * traffic.
 *
 * @note: Enabling DHCP on a down interface will make it come
 * up once configured.
 *
 * @see dhcp_start()
 */
void netif_set_up(struct netif* netif)
{
	if(!(netif->flags & NETIF_FLAG_UP)) {
		netif->flags |= NETIF_FLAG_UP;

#if LWIP_SNMP
		snmp_get_sysuptime(&netif->ts);
#endif /* LWIP_SNMP */

		NETIF_LINK_CALLBACK(netif);
		NETIF_STATUS_CALLBACK(netif);

#if LWIP_ARP

		/* For Ethernet network interfaces, we would like to send a "gratuitous ARP" */
		if(netif->flags & NETIF_FLAG_ETHARP) {
			etharp_gratuitous(netif);
		}

#endif /* LWIP_ARP */

#if LWIP_IGMP

		/* resend IGMP memberships */
		if(netif->flags & NETIF_FLAG_IGMP) {
			igmp_report_groups(netif);
		}

#endif /* LWIP_IGMP */
	}
}

/**
 * Bring an interface down, disabling any traffic processing.
 *
 * @note: Enabling DHCP on a down interface will make it come
 * up once configured.
 *
 * @see dhcp_start()
 */
void netif_set_down(struct netif* netif)
{
	if(netif->flags & NETIF_FLAG_UP) {
		netif->flags &= ~NETIF_FLAG_UP;
#if LWIP_SNMP
		snmp_get_sysuptime(&netif->ts);
#endif

		NETIF_LINK_CALLBACK(netif);
		NETIF_STATUS_CALLBACK(netif);
	}
}

/**
 * Ask if an interface is up
 */
u8_t netif_is_up(struct netif* netif)
{
	return (netif->flags & NETIF_FLAG_UP) ? 1 : 0;
}

#if LWIP_NETIF_STATUS_CALLBACK
/**
 * Set callback to be called when interface is brought up/down
 */
void netif_set_status_callback(struct netif* netif, void (* status_callback)(struct netif* netif))
{
	if(netif)
		netif->status_callback = status_callback;
}
#endif /* LWIP_NETIF_STATUS_CALLBACK */

#if LWIP_NETIF_LINK_CALLBACK
/**
 * Called by a driver when its link goes up
 */
void netif_set_link_up(struct netif* netif)
{
	/* not notify link up anymore */
	if(netif->flags & NETIF_FLAG_LINK_UP) return;

	netif->flags |= NETIF_FLAG_LINK_UP;

#if LWIP_DHCP

	if(netif->dhcp) {
		dhcp_network_changed(netif);
	}

#endif /* LWIP_DHCP */

#if LWIP_AUTOIP

	if(netif->autoip) {
		autoip_network_changed(netif);
	}

#endif /* LWIP_AUTOIP */

	if(netif->flags & NETIF_FLAG_UP) {
#if LWIP_ARP

		/* For Ethernet network interfaces, we would like to send a "gratuitous ARP" */
		if(netif->flags & NETIF_FLAG_ETHARP) {
			etharp_gratuitous(netif);
		}

#endif /* LWIP_ARP */

#if LWIP_IGMP

		/* resend IGMP memberships */
		if(netif->flags & NETIF_FLAG_IGMP) {
			igmp_report_groups(netif);
		}

#endif /* LWIP_IGMP */
	}

	NETIF_LINK_CALLBACK(netif);
}

/**
 * Called by a driver when its link goes down
 */
void netif_set_link_down(struct netif* netif)
{
	netif->flags &= ~NETIF_FLAG_LINK_UP;
	NETIF_LINK_CALLBACK(netif);
}

/**
 * Ask if a link is up
 */
u8_t netif_is_link_up(struct netif* netif)
{
	return (netif->flags & NETIF_FLAG_LINK_UP) ? 1 : 0;
}

/**
 * Set callback to be called when link is brought up/down
 */
void netif_set_link_callback(struct netif* netif, void (* link_callback)(struct netif* netif))
{
	if(netif) {
		netif->link_callback = link_callback;
	}
}
#endif /* LWIP_NETIF_LINK_CALLBACK */

#if ENABLE_LOOPBACK
/**
 * Send an IP packet to be received on the same netif (loopif-like).
 * The pbuf is simply copied and handed back to netif->input.
 * In multithreaded mode, this is done directly since netif->input must put
 * the packet on a queue.
 * In callback mode, the packet is put on an internal queue and is fed to
 * netif->input by netif_poll().
 *
 * @param netif the lwip network interface structure
 * @param p the (IP) packet to 'send'
 * @param ipaddr the ip address to send the packet to (not used)
 * @return ERR_OK if the packet has been sent
 *         ERR_MEM if the pbuf used to copy the packet couldn't be allocated
 */
err_t
netif_loop_output(struct netif* netif, struct pbuf* p,
                  struct ip_addr* ipaddr)
{
	struct pbuf* r;
	err_t err;
	struct pbuf* last;
#if LWIP_LOOPBACK_MAX_PBUFS
	u8_t clen = 0;
#endif /* LWIP_LOOPBACK_MAX_PBUFS */
	SYS_ARCH_DECL_PROTECT(lev);
	LWIP_UNUSED_ARG(ipaddr);

	/* Allocate a new pbuf */
	r = pbuf_alloc(PBUF_LINK, p->tot_len, PBUF_RAM);

	if(r == NULL) {
		return ERR_MEM;
	}

#if LWIP_LOOPBACK_MAX_PBUFS
	clen = pbuf_clen(r);

	/* check for overflow or too many pbuf on queue */
	if(((netif->loop_cnt_current + clen) < netif->loop_cnt_current) ||
	        ((netif->loop_cnt_current + clen) > LWIP_LOOPBACK_MAX_PBUFS)) {
		pbuf_free(r);
		r = NULL;
		return ERR_MEM;
	}

	netif->loop_cnt_current += clen;
#endif /* LWIP_LOOPBACK_MAX_PBUFS */

	/* Copy the whole pbuf queue p into the single pbuf r */
	if((err = pbuf_copy(r, p)) != ERR_OK) {
		pbuf_free(r);
		r = NULL;
		return err;
	}

	/* Put the packet on a linked list which gets emptied through calling
	   netif_poll(). */

	/* let last point to the last pbuf in chain r */
	for(last = r; last->next != NULL; last = last->next);

	SYS_ARCH_PROTECT(lev);

	if(netif->loop_first != NULL) {
		LWIP_ASSERT("if first != NULL, last must also be != NULL", netif->loop_last != NULL);
		netif->loop_last->next = r;
		netif->loop_last = last;
	} else {
		netif->loop_first = r;
		netif->loop_last = last;
	}

	SYS_ARCH_UNPROTECT(lev);

#if LWIP_NETIF_LOOPBACK_MULTITHREADING
	/* For multithreading environment, schedule a call to netif_poll */
	tcpip_callback((void (*)(void*))(netif_poll), netif);
#endif /* LWIP_NETIF_LOOPBACK_MULTITHREADING */

	return ERR_OK;
}

/**
 * Call netif_poll() in the main loop of your application. This is to prevent
 * reentering non-reentrant functions like tcp_input(). Packets passed to
 * netif_loop_output() are put on a list that is passed to netif->input() by
 * netif_poll().
 */
void
netif_poll(struct netif* netif)
{
	struct pbuf* in;
	SYS_ARCH_DECL_PROTECT(lev);

	do {
		/* Get a packet from the list. With SYS_LIGHTWEIGHT_PROT=1, this is protected */
		SYS_ARCH_PROTECT(lev);
		in = netif->loop_first;

		if(in != NULL) {
			struct pbuf* in_end = in;
#if LWIP_LOOPBACK_MAX_PBUFS
			u8_t clen = pbuf_clen(in);
			/* adjust the number of pbufs on queue */
			LWIP_ASSERT("netif->loop_cnt_current underflow",
			            ((netif->loop_cnt_current - clen) < netif->loop_cnt_current));
			netif->loop_cnt_current -= clen;
#endif /* LWIP_LOOPBACK_MAX_PBUFS */

			while(in_end->len != in_end->tot_len) {
				LWIP_ASSERT("bogus pbuf: len != tot_len but next == NULL!", in_end->next != NULL);
				in_end = in_end->next;
			}

			/* 'in_end' now points to the last pbuf from 'in' */
			if(in_end == netif->loop_last) {
				/* this was the last pbuf in the list */
				netif->loop_first = netif->loop_last = NULL;
			} else {
				/* pop the pbuf off the list */
				netif->loop_first = in_end->next;
				LWIP_ASSERT("should not be null since first != last!", netif->loop_first != NULL);
			}

			/* De-queue the pbuf from its successors on the 'loop_' list. */
			in_end->next = NULL;
		}

		SYS_ARCH_UNPROTECT(lev);

		if(in != NULL) {
			/* loopback packets are always IP packets! */
			if(ip_input(in, netif) != ERR_OK) {
				pbuf_free(in);
			}

			/* Don't reference the packet any more! */
			in = NULL;
		}

		/* go on while there is a packet on the list */
	} while(netif->loop_first != NULL);
}

#if !LWIP_NETIF_LOOPBACK_MULTITHREADING
/**
 * Calls netif_poll() for every netif on the netif_list.
 */
void
netif_poll_all(void)
{
	struct netif* netif = netif_list;

	/* loop through netifs */
	while(netif != NULL) {
		netif_poll(netif);
		/* proceed to next network interface */
		netif = netif->next;
	}
}
#endif /* !LWIP_NETIF_LOOPBACK_MULTITHREADING */
#endif /* ENABLE_LOOPBACK */
